Onchocerciasis in Imo State, Nigeria; Clinical and epidemiological studies of anterior segment lesions

Abstract

A clinical and epidemiological assessment of Ocular Onchocerciasis with respect to Anterior Segment Lesions (ASLs) was carried out in 7348 consenting persons living in 38 rural communities in the Imo River Basin of Nigeria between March 1999 and September 2000. the results showed that 40.0% (2934/7348) of the subjects had one form of ASLs. Blurring of vision (10.1%) was the most prevalent lesion followed by anterior uveitis (8.5%) while the least was blindness (with no light perception) (0.2%). ASLs were absent in the 0-9 year group but increased in relation to microfilarial density (mfd) in the older age groups. Sex-prevalence of ASLs showed insignificant borderline differences in all case (p>0.038). Blindness was weakly associated with mfd (r=0.32;p<0.038), while sclerosing keratitis (r=0.67;p<0.001), punctuate opacity (r=0.53; p<0.001) and anterior uveitis (r=0.64;p<0.001) was strongly associated with mfd. The results show that Ocular Onchocerciasis is also a major health problem in the rainforest zone. This underscores the need for sustenance of control effects in the area.

The Nigerian Journal of Parasitology Vol. 24 2003: 89-94